This invention relates to composite diamond abrasive compacts.
A composite diamond abrasive compact consists of a diamond compact bonded to a cemented carbide support. The diamond compact consists of a polycrystalline mass of diamond particles and optionally a second phase. When a second phase is provided the phase will generally contain or consist predominantly of a diamond catalyst such as cobalt. The diamond content of a diamond compact will generally be greater than 70% by volume of the compact.
Composite diamond abrasive compacts and their method of manufacture are well known in the art and are described in the patent literature. Examples of relevant patent specifications in this regard are U.S. Pat. No. 3,745,623 and British Patent No. 1,489,130. The disclosures of these two patent specifications are incorporated herein by reference.
Composite diamond abrasive compacts are used as inserts for various tools such as turning, grinding and cutting tools. The cemented carbide support will be brazed or otherwise bonded to the tool while the diamond compact will provide a cutting edge or point.
Composite diamond abrasive compacts are made under elevated temperature and pressure conditions at which diamond is crystallographically stable. In producing these compacts either fine or coarse diamond particles are used depending on the desired end use. Problems have been encountered in producing composite diamond abrasive compacts using fine diamond particles. It has been found difficult to avoid imperfect sinter areas developing within the diamond compact layer and the presence of such imperfect sinter areas is deleterious to the performance of the product.